1. Field of the Invention
The invention relates to a bicycle wheel, more particularly to a spoke fastener for mounting an externally threaded end of a spoke to a wheel rim.
2. Description of the Related Art
In a bicycle, a wheel rim is usually connected to a hub by a set of spokes.
As shown in FIG. 1, a spoke 1 has a threaded end 101 connected to a wheel rim 2 using a conventional spoke fastener 3 that includes a spoke connecting member 301 and a rim connecting member 302. The spoke connecting member 301 is in the form of an internally threaded socket for engaging the threaded end 101. The rim connecting member 302 is in the form a headed bolt that connects the spoke connecting member 301 to the wheel rim 2. The conventional spoke fastener 3 is disadvantageous in that it involves more than one component and is relatively troublesome to install.
FIG. 2 shows another conventional connection between a spoke 4 and a wheel rim 5. The wheel rim 5 is formed with a set of spoke connecting blocks 501. The spoke 4 extends through a respective one of the spoke connecting blocks 501, and has a head end 401 stopped by the respective spoke connecting block 501. However, since the wheel rim 5 is typically formed by extrusion, additional finishing operations are required to form the spoke connecting blocks 501, which results in a complicated manufacturing process and in increased manufacturing costs.
Therefore, the object of the present invention is to provide a spoke fastener for use in a bicycle wheel so as to overcome the aforesaid drawbacks of the prior art.
Accordingly, a spoke fastener of this invention is adapted for mounting an externally threaded end of a spoke to a wheel rim which has a spoke mounting wall formed with a spoke fastening hole that is larger than the cross-section of the externally threaded end of the spoke. The spoke fastener comprises a shank extending along a shank axis and having an anchoring portion and an operating portion.
The anchoring portion is formed with a set of resilient arm segments, each of which extends parallel to the shank axis and has a connecting end connected to the operating portion and a distal end opposite to the connecting end along the shank axis. The arm segments are angularly spaced apart from each other relative to the shank axis. The distal end of each of the resilient arm segments is formed with a radial outward anchor projection. The anchor projections on the resilient arm segments cooperate to form the anchoring portion with an initial cross-section in a relaxed state of the resilient arm segments, the initial cross-section being larger than the spoke fastening hole. The anchor projections on the resilient arm segments are forcible radially and inwardly toward the shank axis in such a manner that the anchor projections cooperate to form the anchoring portion with a restricted cross-section smaller than the spoke fastening hole, thereby permitting extension of the anchoring portion through the spoke fastening hole and retention of the anchoring portion on the spoke mounting wall.
The shank is formed with a through hole that extends along the shank axis through the operating and anchoring portions and that permits extension of the externally threaded end of the spoke into the shank from the operating portion. The through hole has an internally threaded segment so as to enable the shank to threadedly engage the externally threaded end of the spoke.